8
R-320BB
R-320BK
R-320BW
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
control panel, refer to the Figure D-1.
When the open button is pushed, the open button pushes up
the switch lever, and then the switch lever pushes up the
latch head. The latch heads are moved upward and re-
leased from latch hook. Now the door will open.
Latch Hook
Door
Sensing
Switch
Monitor
Switch
Secondary
Interlock
Switch
Switch
Lever
Latch
Heads
Door
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The secondary interlock switch is mounted in the lower
position of the latch hook and the door sensing switch in the
primary interlock system is mounted in the upper position of
the latch hook. They are activated by the latch heads on the
door. When the door is opened, the switches interrupt the
power to all high voltage components. A cook cycle cannot
take place until the door is firmly closed thereby activating
both interlock switches. The primary interlock system con-
sists of the door sensing switch and primary interlock relay
located on the control circuit board.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the
latch head on the door while the door is closed. The switch
is intended to render the oven inoperative, by means of
blowing the monitor fuse, when the contacts of the primary
interlock relay (RY2) and secondary interlock switch fail to
open when the door is opened.
Functions:
1. When the door is opened, the monitor switch contact
close (to the ON condition) due to their being normally
closed. At this time the primary interlock relay (RY2) and
secondary interlock switch are in the OFF condition
(contacts open) due to their being normally open contact
switches.
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing
switch and the secondary interlock switch contacts close.
(On opening the door, each of these switches operate
inversely.)
3. If the door is opened, and the primary interlock relay
(RY2) and secondary interlock switch contacts fail to
open, the monitor fuse blows simultaneously with closing
of the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE TEST THE DOOR SENSING SWITCH,
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. COOKING TIME PROGRAMMED
3. VARIABLE COOKING CONTROL "HIGH"
4. "START" PAD TOUCHED
Figure O-2. Oven Schematic-Cooking Condition
OVEN
LAMP
TURN-
TABLE
MOTOR
FAN
MOTOR
POWER
TRANSFORMER
MONITOR
SWITCH
RECTIFIER
MAGNETRON
SECONDARY
INTERLOCK
SWITCH
TTM
OL
FM
COM.
N.O.
DOOR
SENSING
SWITCH
SH-B
SH-A
(RY-1)
(RY-2)
CONTROL UNIT
PRIMARY
INTERLOCK
RELAY
120V AC
60 Hz
GRN
MONITOR
FUSE 20A
THERMAL
CUT-OUT (OVEN)
THERMAL
CUT-OUT (MG.)
COM.
CAPACITOR 1.0
µ
F
AC 2300V
A1
A2
N.O.
F3
F1
F2
AH SENSOR
